Typewriting machine



R. G. THOMPSON 2,63,53@ TYPEWRITING MACHINE Filed March 18, 1931 2 Sheets-Sheet l NI & 79L w m w o s Q 0 0 W why 1 o o a Q Q 3 Q t \S om Q n J mm mm /v m N N 9 Dec. &, was,

'INVENTOR RU SELL s. THOMPSON ATTORNEY Dec. 8, 1936. R. G. THOMPSON TYPEWRITING MACHINE Filed March 18, 1931 2 Sheets-Sheet 2 INVENTOR v RUSSELL e. THOMPSON ATTORNEY B mm 1? wm hm hm Nm S ow om \m w Patented Dec 8, 1936 UNITED STATES PATENT OFFICE- to Electromatic Typewriters, Inc., Rochester,

N. Y., a corporation of New York Application March 18,

12 Claims.

This invention relates to improvements in typewriting machines, and particularly to such machines as are driven by power means, such as electric motors.

The principal object of this invention is to provide simple means which are automatically actuated for maintaining a constant driving speed under varying load conditions.

Machines of this type are equipped with means for automatically selecting and controlling the type action, said means comprising a master sheet roller and a master sheet arranged thereon, hand operated means being provided for connecting and disconnecting the master sheet roller with its driving means, so that the machine can be manually operated when desired. It is the object of this invention to provide means which tends to speed up. the motor when the master sheet roller is connected with the driving means and to reduce its speed when the master sheet roller is disconnected from the driving means, with the result that the motor is driven at a'substantially constant speed, resulting in uniform type impressions.

To these and other ends, the invention consists in the construction and arrangement of parts that will appear from the following description when read in conjunction with the accompanying drawings, the novel features being so pointed out in the claims at the'end of the specification.

In the drawingsz' Fig. 1 is a transverse sectional view of an electrically driven typewriting machine illustrating one embodiment of the invention;

Fig.2 is a diagram of the electric wiring of the motor shown in Fig. lfand Fig. 3 is a view similar to Fig. 1 but illustratinganother way of carrying out the invention.

Referring specifically to the drawings, in which like reference numerals refer to the same part in all the views, 1 indicates the-frame of the machine in which the key levers 2 are pivotally mounted. The key levers are provided with keys 3 whereby they may be manually actuated for operating printing inStrumentalities.

comprising type bars of-usual construction. The

I type bars are actuated by power driven means comprising a roller 4 operatively connected with the shaft 5 of an electric motor 6 to be driven thereby. Mounted on one arm of a bell crank lever I adjacent the roller 4 is a cam 8 resiliently urged into engagement with the roller,.but retained out of engagement thereby by key controlled means comprising a lever. 9 pivotally 1931, Serial No. 523,481

mounted on the bell crank -l and. engaging a lug projecting laterally from the cam. At its upper end, the lever 9 has a laterally projecting lug operatively engaged by the key lever 2 whereby it may be actuated out of andintothe path of 5 the lug on the cam 8. When the cam 8 moves into engagement with the roller, it turns on the bell crank and cams its arm away from the roller and swings the bell crank on its pivot. The other arm of the bell crank is operatively 10 connected with its type bar by means of the link I 0. v i

Means also adapted to be driven by the motor 6 are provided for selectively actuating the key levers 2. Said meanscomprises a lever Ii pivoted on the frame and having one end slidably connected with the key lever by means of a link I! so that when the key lever is manually actuated, it slides on the link, but when the lever II is actuated it depresses the key lever to connect its type bar with the motor driven devices previously described. Rvolubly mounted on the lever is a star wheel H! which normally engages a master'perforated sheet [4 arranged on a roller l5 also adapted to be driven by the motor 6. The surface of the roller 15 is provided with depressions I6 so that when a perforation in the sheet It meets an arm of a star wheel I3, the arm moves through the sheet into engagement with a depression in the roller which is operative to turn the star wheel and swing the lever H to depress the key lever. A spring l1 connects the lever H with a fixed part and resiliently retains the star wheel in contact with I the roller I5 or the master sheet thereon. A worm wheel is operatively connected with the shaft of the roller 15, which worm wheel is operatively connected with a,worm ona shaft l8 arranged in axial alinement with the -shaft 5. The forward end of the shaft 5 is provided with 40 a clutch member l9, and a cooperating clutch member 20 is splined on the rear end of the shaft l8 so that'it is slidable axially thereon to and from engagement with the clutch member i! but is fixed to the shaft to rotate therewith. Manually operated means comprising a lever 2| are provided for actuating the clutch member 20. The lever 2|v is pivoted on a fixed part and is manually operable to move the clutch memher '20 to and from operative engagement with its cooperating clutch member iii to operatively connect or disconnect the roller IS with the motor driven devices. The parts thus far described are of usual or well known construction,

" iii: means.

In a machine of this kind, it is important that t the speed of the motor be maintained substan- 5 tially constant to insure uniform type impressions-on the work sheet. In using such a machine, however, it is the usual practice to open the clutch to throw the master sheet operator out of operation to write the heading, fill ins, etc. of a letter manually by actuating the keys 3, after which the clutch is closed to" write other parts of the letter. When the clutch is closed to operate the master sheet devices with the motor, a greater load is thrown on the motor which has a tendency to slow it up or reduce its speed. When, however, the clutch is opened to disconnect the master sheet devices from operatlve connection with the motor, the load on the motor is reduced which has a tendency to increase its speed. As a result, the headings and other parts of the writing which are manually se--.

lected are impressed more heavily than the master sheet*selected parts. Means are therefore provided for automatically controlling the speed 25 of the motor. This may be done in different ways, and in the embodiment illustrated in Figs. 1 and 2, the speed of the motor is controlled electrically by means actuated automatically by the clutch lever.

Referring to the diagram in Fig. 2, it will be noted that the motor 6 is arranged in series with a source of power, and a manually actuated rheostat 25 is arranged in a shunt 24 aroundthe motor. 25, the motor may be operated at the desired speed. A main switch 26 controls the motor. A second or auxiliary rheostat 21 is also arranged in the shunt 24 and controlled by means of a switch 28. When the switch 28 is open, additional resistance is arranged in the shunt circuit which decreases the current through the shunt and increases the current through the motor and increases its speed. When, however,-

.the switch 28 is closed, the auxiliary rheostat is shorted and the current is increased in the shunt and reduced through the motor, thus reducing the motor speed.

Means automatically controlled by the clutch lever are provided for actuatingthe switch 28. To this end, the switch is operatively connected with ,theclutch lever 2| by means of a link 29, so arranged that the switch 28 is closed when the clutch is disengaged, and automatically opened when the lever is operated to engage the clutch. By this arrangement, the switch 28 is closed when the power operated roller l5 and associated devices are disconnected from operative connection with the motor and the auxiliary resistance is cut off. When, however,

the clutch is closed to connect the roller I with the motor to be driven thereby, the switch is opened and the auxiliary resistance is thrown 'into theshunt circuit, thus increasing the current through the motor to maintain its speed constant with the'additional load. I i In Fig. 3 of the drawings, a modified arrangem'entis illustrated in which the speed of the amotor is controlled automatically by friction In the illustrated embodiment, a disk 7 j=- or..plate 30is mounted on guide posts 3| pro- .-'jec,ting from a fixed .part.. The plate 30 is held against rotation by the posts 3| but is ad- ,J'ustable axially thereon, and has a central opening 32 therein through which the motor shaft 75 5 .extends. Fixed-t0. the side of the plate 30 By adjusting the rheostat,

-opening in a fixed part of the frame.

is a friction disk 33 with which a disk or plate 34 mounted on the shaft 5 cooperates. disk 34 is splined on the shaft 5 to rotate therewith, but is slidable thereon into and out of engagement with the disk 33. It will be understood that when the disk 34 on the shaft 5 engages the fixed friction disk, it operates as a brake to resist the rotation of the shaft and tends to reduce the speed of rotation of the shaft.

Automatic means controlled by the speed of rotation of the shaft are provided for moving the disk 34 to and from engagement with the friction disk 33. To this end, the disk 34 is provided with a laterally projecting hub 35 whereby it is connected with a sleeve or thimble 36 by means of a pair of diametrically arranged resilient straps 31 having weights 38 secured thereto intermediate their ends. The sleeve 36 is secured to the shaft 5 to rotate therewith and -fixed against axial movement thereon. When the shaft 5 is rotated, the weights 38 tend to move radially away from the shaft against the tension of the straps 31 and to pullthe disk 34 into engagement with the friction disk 33. It will be noted that the centrifugal force exerted by the weights 38 varies directly with the speed of the motor and that the braking action or friction between the disks 33 and 34 also varies with this centrifugal force so that the resulting action is to maintain a constant motor speed.

Means areprovided for adjusting the plate 30 on the posts 3| and with it the friction disk 33 secured thereto toward and from the disk 34 to determine the point in the movement of the disk 34 at which it engages the friction disk which determines the normal maximum speed of the motor. To this end, a bell crank lever 40 is pivoted on the frame, and has a downwardly projecting arm 4|. The arm 4| is bifurcated to straddle the shaft 5 and is pivotally connected with the plate 30 on opposite sides of its opening 32. The other arm 42 of the bell crank projects forward from its pivot and at its free end engages a set screw 43 arranged in a tapped By this arrangement, the screw 43 serves as a stop for limiting the forward movement of the friction disk away from the disk 34. When the set screw 43 is turned in one direction, the plate 30 is adjusted toward the disk 34 and the braking action is applied to the motor at a lower speed; when the screw is turned in the opposite direction, the plate 30 is permitted to move axially away from the disk 34 and a greater motor speed is necessary to move. the disk 34 into engagement with the friction disk.

By this arrangement, if the motor speeds up to such an extent as to make the impressions on the work sheet too heavy when the clutch is disengaged to disconnect the roller l5 from driving connection therewith, the disk 34 is automatically engaged with the frictiondi'sk 33 to brake or reduce the speed of the motor until said impressions are uniform with those produced a when the clutch -is closed.

Although only two embodiments of the invention are shown and described herein, it will be The plication is intended to cover such changes or modifications as come within the spirit of the invention or scope-of the following claims.

I claim:

1. In a power driven typewriting machine, the

combination with printing instrumentalities, of adriven roller, key controlled meansfor operatively connecting said printing instrumentalities with the driven roller, a motor for driving said roller, power driven devices for selectively actuating said key controlled means, a hand operated device for operatively connecting and disconnecting said power driven devices with said motor, and means controlled by said hand operated device for controlling the speed of the motor.

2. In a power driven typewriting machine, the combination with printing instrumentalities, of a driven roller, key controlled means for operatively connecting said printing instrumentalities with the driven roller, a motor for driving said roller, power driven devices for selectively actuating said key controlled means, a hand operated device for operatively connecting and disconnecting said power driven devices with said motor, and means operatively connected with said hand operateddevice for controlling I the speed of the motor.

3. In a power driven typewriting machine, the combination with printing instrumentalities, of a driven roller, key controlled means for operatively connecting said printing instrumentalities with the driven roller, an electric motor for driving said roller, a rheostat for controlling the speed of said motor, power driven devices for actuating said key controlled means, a manually actuated device for connecting the power driven devices with the motor to be driven thereby, and means operated by said manually actuated device for controlling the operation of said rheostat.

4. In a power driven typewriting machine, the combination with printing instrumentalities, of a driven roller, key controlled means for operatively connecting said printing instrumentalities with the driven roller, an electric motor for driving said roller, a rheostat for controlling the speed of said motor, a switch for controlling the operation of the rheostat, power driven devices for actuating said key controlled means, a man ually actuated device for connecting the power driven devices with the motor to be driven thereby, and means operatively connecting said switch with said manually actuated device.

5. In a power driven typewriting machine, the combination with printing instrumentalities, of a driven roller, key controlled means for operatively connecting said printing instrumentalities with the driven roller, an electric motor for driving said roller, a rheostat for controlling the speed of said motor, a switch for controlling the operation of the rheostat, power driven devices for actuating said key controlled means, a clutch for connecting the power driven devices with the motor to be driven thereby, manually actuated means for operating said clutch, and a link operatively connecting said switch with said manually actuated means.

6. In a power driven machine, the combination with printing instrumentalities, of a driven roller, key controlled means'for operatively con necting said printing instrumentalities with the driven roller, an electric motor for driving said roller, a master sheet roller for selectively operating said key controlled means, manually op- 'erated means for connecting 'or disconnecting said master sheet roller with the motor to be driven thereby, a rheostat for controlling the speed of the motor, and means actuated by said manually operated means for controllingthe operation of the rheostat to limit the speed of the motor to secure substantially uniform impressions by the printing instrumentalities.

7. In a machine of the class described, recording elements, a power actuator, a motor for operating said actuator, selecting devices for manually selectively connecting the recording elements to said actuator for operation by the latter, an automatic controller operable by said motor for automatically selectively operating the selecting devices, means for coupling the motor to the automatic controller whereby the actuator and controller are both operated by the motor, and means controlled by the coupling means for controlling the speed of the motor in accordance with the additional load imposed thereon by the automatic controller.

8. In combination, recording elements, a power operator for said elements, selectively operable elements for selectively connecting the recording elements to the power operator for operation by the latter, a motor for driving the power operator, a master sheet and means controlled by movement of the master sheet for automaticallyselectively operating the selectively operable ele- 'ments, means for feeding the master sheet,

means for coupling the. master sheet feeding means to said motor including a control element for the coupling means, and means connected to said control element for controlling the speed of the motor.

9. In an automatic power driven typewriting machine, a driving motor, power operated printing mechanism actuated by said motor including character printing means and selecting devices operable selectively to control the printing of characters by the printing means, an automatic typewriter operator adapted to be driven by the motor and when so driven selectively actuating the selecting devices to cause automatic printing of predetermined data set up in said operator; 9. device for coupling the typewriter operator to the motor when automatic operation of the printing mechanism is desired, thereby imposing an additional load on the motor tending to reduce its speed; and means controlled by said coupling device for changing the value of the current supplied to the motor whereby to compensate for the additional load on the motor imposed by the automatic typewriter operator.

10. In combination, recording mechanism, actuating means therefor, electric power means for operating said actuating means, means for couthe additional load on the power means when the latter drives the automatic control means.

11. In combination,

recording mechanism;

power means to operate said mechanism including a power operator, a power unit for said operator, and means to selectively control the operation of the recording mechanism by the power operator, said power unit normally operating the power operator at a definite speed, an auxiliary control device operable by the power unit and adapted to operate the selective control means automatically and when operated by said unit tending to increase the load on said unit and reduce its speed, control means for at will connecting the auxiliary device to the power unit, and means connected to the control means for controlling the speed at which the power unit drives said operator whereby to compensate for the increased load imposed on the power unit by the auxiliary control device.

12. In combination, recording mechanism;

power means for operating the recording mechanism, including a propulsion unit therefor, and means to selectively control the operation of the recording mechanism by the power means, one of said control means being automatic and when coupled to the propulsion unit tending to impose additional load on said unit; means to couple said automatic control means to said unit whereby said unit drives the power means and automatic control means together, and means controlled by operation of the coupling means for preventing change in the speed of the propulsion unit when the automatic control means is coupled to said unit.

RUSSELL G. THOMPSON. 

